MR2 Roadster - A Tale Of Woe, Maybe...
Discussion
Martin350 said:
From what I've seen they aren't bad at all for rust.
I checked the MOT history for mine before I bid on it and there was no mention of it.
And my other half's 2004 model was very tidy underneath when she sold it last year.
Rear anti roll bars corrode, but it's not much to worry about.
From experience I can say that the MR2 is far cheaper to run than a 350Z.
There's the fuel for a start, especially considering a 350Z should be run on higher octane petrol.
Also prices of some parts like brakes and service items and any repairs are generally higher with the Nissan. And there's tax and insurance to consider.
A good MR2 should really be quite a cheap car to run.
As a weekend car I'd say the MR2, although very different and obviously not as powerful as the 350Z, is in some ways a lot more fun.
The MR2 is a sports car, the 350Z is a GT.
Sounds good I checked the MOT history for mine before I bid on it and there was no mention of it.
And my other half's 2004 model was very tidy underneath when she sold it last year.
Rear anti roll bars corrode, but it's not much to worry about.
From experience I can say that the MR2 is far cheaper to run than a 350Z.
There's the fuel for a start, especially considering a 350Z should be run on higher octane petrol.
Also prices of some parts like brakes and service items and any repairs are generally higher with the Nissan. And there's tax and insurance to consider.
A good MR2 should really be quite a cheap car to run.
As a weekend car I'd say the MR2, although very different and obviously not as powerful as the 350Z, is in some ways a lot more fun.
The MR2 is a sports car, the 350Z is a GT.
That was my assumption on the vehicles too. My 2nd car was a Mk2 MR2 which I enjoyed despite the moon mileage it had. 
Update time!
I got home this evening, did a compression test. The results were very surprising to me, I've never tested an engine and got more consistent results, all four were almost exactly the same!
Full of confidence, I put the cam cover and exhaust manifold back on, new spark plugs in and fired it up, and.....
... it still knocked like a good 'un!
I left it idling and did a quick as possible screwdriver-o-scope test on the cylinder head next to all four cylinders, and it seems there is still an issue with cylinder four, the one with the broken spark plug.
I had another hour or so to spare and made quite a good start on getting the cylinder head off, bugger!
I got home this evening, did a compression test. The results were very surprising to me, I've never tested an engine and got more consistent results, all four were almost exactly the same!
Full of confidence, I put the cam cover and exhaust manifold back on, new spark plugs in and fired it up, and.....
... it still knocked like a good 'un!
I left it idling and did a quick as possible screwdriver-o-scope test on the cylinder head next to all four cylinders, and it seems there is still an issue with cylinder four, the one with the broken spark plug.
I had another hour or so to spare and made quite a good start on getting the cylinder head off, bugger!
Something jammed in the head is my first thought, but sometimes with things like this it's something completely different and totally unexpected.
It's definitely not an engine mount, it's something inside cylinder four.
I'll get a bit more done this evening but I'm aiming to have the head off some time on Saturday, hopefully.
It's definitely not an engine mount, it's something inside cylinder four.
I'll get a bit more done this evening but I'm aiming to have the head off some time on Saturday, hopefully.
Machinemart sell longer splines and tore if you have one near you. Or obviously off ebay if can wait for it to be posted
https://www.machinemart.co.uk/p/cht144-40-pce-torx...
https://www.machinemart.co.uk/p/cht144-40-pce-torx...
Thanks chaps, appreciate your help and support!
As it happens, my mate who I was with this afternoon had a longer spliney tool thingy!
So, off with its head!
And....
Well, not a lot at first glance;
On closer inspection, there was a small piece of hard metal, I suspect the mashed up spark plug electrode, on top of a slightly dented piston.
And that is another smaller bit of metal to the left of it.
And slight denting to the head, to the right of the two smaller exhaust valves.
So, was the knocking noise the small bit of shrapnel being bashed?
Or is it a little end, or piston, or piston ring..?
I'm tempted to get the sump off again and take the piston out for a look.
As it happens, my mate who I was with this afternoon had a longer spliney tool thingy!
So, off with its head!
And....
Well, not a lot at first glance;
On closer inspection, there was a small piece of hard metal, I suspect the mashed up spark plug electrode, on top of a slightly dented piston.
And that is another smaller bit of metal to the left of it.
And slight denting to the head, to the right of the two smaller exhaust valves.
So, was the knocking noise the small bit of shrapnel being bashed?
Or is it a little end, or piston, or piston ring..?
I'm tempted to get the sump off again and take the piston out for a look.
Edited by Martin350 on Sunday 15th May 22:05
I did do that.
This evening I drained the brand new oil, took the sump and oil pick up pipe off and removed piston 4, the naughty one!
It doesn't look great, but it is a few hundred miles short of 100,000.
No broken rings, no detectable by hand play in the gudgeon pin, but it is a worn piston which has taken a bit of a hammering.
This is a better view of the piece of, probably, spark plug electrode. It's about 9mm long.
Do you like the hologram dinosaur ruler? They change position as you tilt the ruler, some of them are fighting!
It's about 2mm thick, measured with verniers, not the dinosaur ruler.
Slightly better view of the big end shell, looks good to me.
Now, these engines have been known to suffer with the bores ovaling, due to issues with the piston rings, oil holes in the pistons blocking and pre-cat failures.
It's all a bit chicken and egg, and I don't think anyone knows for sure what happens first.
Mine clearly didn't have a pre-cat issue, and with the rings off and the oil holes checked, nothing here either.
But the piston does show evidence of piston ring blow by.
Although, my mate who followed me home from collecting the car told me there was no smoke at all from the exhaust.
So, do I;
- Put it all back together now and hope the knocking noise was caused by the errand bit of metal
- Hone the bores and put new piston rings in, they won't bed in properly if the bores have ovaled
- Get hold of tools to tell me if the bores are ovaled (might be a good idea!)
- Get a new engine
- Open a bottle of red
With a car of such low value, it's tricky deciding how far I'm willing to go both financially and time wise, but I do want it running and working well...
This evening I drained the brand new oil, took the sump and oil pick up pipe off and removed piston 4, the naughty one!
It doesn't look great, but it is a few hundred miles short of 100,000.
No broken rings, no detectable by hand play in the gudgeon pin, but it is a worn piston which has taken a bit of a hammering.
This is a better view of the piece of, probably, spark plug electrode. It's about 9mm long.
Do you like the hologram dinosaur ruler? They change position as you tilt the ruler, some of them are fighting!
It's about 2mm thick, measured with verniers, not the dinosaur ruler.
Slightly better view of the big end shell, looks good to me.
Now, these engines have been known to suffer with the bores ovaling, due to issues with the piston rings, oil holes in the pistons blocking and pre-cat failures.
It's all a bit chicken and egg, and I don't think anyone knows for sure what happens first.
Mine clearly didn't have a pre-cat issue, and with the rings off and the oil holes checked, nothing here either.
But the piston does show evidence of piston ring blow by.
Although, my mate who followed me home from collecting the car told me there was no smoke at all from the exhaust.
So, do I;
- Put it all back together now and hope the knocking noise was caused by the errand bit of metal
- Hone the bores and put new piston rings in, they won't bed in properly if the bores have ovaled
- Get hold of tools to tell me if the bores are ovaled (might be a good idea!)
- Get a new engine
- Open a bottle of red
With a car of such low value, it's tricky deciding how far I'm willing to go both financially and time wise, but I do want it running and working well...
Edited by Martin350 on Tuesday 17th May 01:26
id smooth off any burrs with a small file and put it back together
if matey said no smoke then no probs , its only a cheap car and even if it does start to use oil you can run it about all summer while you look at the options , a used engine will be much the same and a rebuilt one more than the car is worth
if matey said no smoke then no probs , its only a cheap car and even if it does start to use oil you can run it about all summer while you look at the options , a used engine will be much the same and a rebuilt one more than the car is worth
I had a similar decision to make - my MR2 in blue, was £600 with a knackered engine. (Mine is on a W reg to). I ended up fitting a late model engine from a couple of lads in Birmingham, who specialise in breaking MR2's. I wanted a late model to get around the precat issue and the oval bore problem. £350 for an engine from a 2005 car IIRC, and it's running like a good un.
PM me if you want the number.
PM me if you want the number.
Thanks for the comments.
I think I will try and measure the clearance from piston to head to find out if the piece of metal found on top of the piston is thick enough for contact to be made.
If it is then I'll probably just put it back together and try it.
Thanks bearman, I'll keep that in mind if it doesn't go well!
I think I will try and measure the clearance from piston to head to find out if the piece of metal found on top of the piston is thick enough for contact to be made.
If it is then I'll probably just put it back together and try it.
Thanks bearman, I'll keep that in mind if it doesn't go well!
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